JP2016145931A - Housing for optical device and optical device unit - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a housing for an optical device capable of securely sealing the inside and preventing deterioration in properties of the optical device.SOLUTION: The housing for an optical device includes: a container portion 30 for storing an optical device 10 connected to optical fiber 11 while leading out the optical fiber 11 extending in a front-to-back direction, having side surfaces standing upward around a bottom surface 5 below, and including a slit 34 extending upward from below and opening upward, formed at one of front and rear side surfaces; a box-shaped lid member 20 opening downward, having a slit 24 extending downward from above and opening downward; and a tongue plate member 41 installed inside the container portion 30. The lid member 20 is fitted from the outside of the container portion 30, covering the whole side surfaces of the container portion 30. The slit 24 and the slit 34 form a rectangular opening for causing the inside and the outside of a housing 1a to communicate with each other, and leading out the optical fiber 11. The plate member 41 includes a slit 42 having such a width as to be in contact with the periphery of the optical fiber 11, and the plate member abuts an inner surface around the slit 24.SELECTED DRAWING: Figure 4

Description

  The present invention relates to a housing for housing an optical device to which an optical fiber is connected in a sealed state, and an optical device unit in which the optical device is housed in the housing.

  For example, various optical elements (prisms, mirrors, etc.) between a plurality of optical fiber ports formed with an optical path, such as an optical switch for connecting and blocking an optical path formed between a plurality of optical fiber ports or switching an optical path. An optical device having a Faraday rotator, a polarizer, etc.) is greatly deteriorated in optical characteristics when foreign matter is mixed in the optical path. If metal parts are used, rust may be generated by moisture in the atmosphere. Therefore, an optical device is often provided in the form of an optical device (hereinafter referred to as an optical device unit) that is sealed in a housing while leading out an optical fiber. In particular, mechanical optical devices that connect, shut off, or switch the optical path by interposing a prism or mirror on the optical path by an actuator that uses a coil or the like can cause malfunction if foreign matter enters the moving part. In addition, since many members and parts made of metal are used, it is an indispensable condition to store them in the housing.

  FIG. 1 shows an example of an optical device casing (hereinafter also referred to as a casing 1). Here, an optical device unit 100 in which an optical device is housed in the housing 1 is shown, and FIGS. 1A and 1B are perspective views when the optical device unit 100 is viewed from different directions. The casing 1 has a box-shaped outer shape, and a rectangular opening 4 is formed on end faces (2, 3) facing each other. The optical fiber 11 connected to the optical device housed inside the housing 1 is led out through the opening 4.

  Here, the front and rear directions are defined as shown in the figure, with the direction in which the optical fiber 11 is led out as the front-rear direction. 1A is a perspective view when viewed from the front upper side, and a vertical direction is defined as a perspective view when FIG. 1B is viewed from the rear lower side. The bottom surface of the housing 1 is the bottom 5. The direction perpendicular to the vertical and front-rear directions is defined as the left-right direction, and the left and right directions are defined by the directions when viewed from the front to the rear. Therefore, in the housing 1 shown here, a rectangular opening 4 having a long side in the vertical direction is formed on the left side of the front and rear end faces (2, 3).

  FIG. 2 is an exploded perspective view showing the internal structure of the housing 1. As shown in FIG. 2, the casing 1 has a box-shaped lid member 20 having a top surface 21 and opening downward, and a box-shaped container portion having a bottom surface (31i, 31o) and opening upward. 30. The front and rear surfaces (22, 23) of the lid member 20 are formed with slits (hereinafter also referred to as lid-side slits 24) that extend downward from the vicinity of the top surface 21 and are released at the lower end. On the other hand, the front and rear surfaces (32, 33) of the container part 30 have slits (hereinafter also referred to as container-side slits 34) that extend upward from the vicinity of the inner bottom surface (hereinafter also referred to as the inner bottom surface 31i) and are released at the upper end. Is formed. In the optical device 10 accommodated in the container part 30, an optical fiber 11 extending forward and backward is connected to each of a front end and a rear end via a connection member 12. Then, when the optical device 10 is housed in the container part 30 so that the optical fiber 11 is led out to the outside through the container-side slit 34, and then the cover member 20 is put on the container part 30 to assemble the housing 1, The rectangular opening 4 described above is formed at both front and rear ends (2, 3) of the body 1, and the optical fiber 11 is led out through the opening 4.

  Further, since the optical device 10 in the housing 1 dislikes foreign matter and moisture, the opening 4 in the housing 1 and the outer bottom surface (hereinafter also referred to as the outer bottom surface 31o) of the container portion 30 shown in FIG. A seam 6 between the outer periphery and the inner periphery of the lower end of the lid member 20 is filled with a sealant such as an adhesive and is cured to seal the inside of the housing 1. The following Patent Documents 1 and 2 describe a mechanical optical switch and a structure of a housing for housing it.

Japanese Patent No. 3870754 Japanese Patent No. 4655045

  In the case for the optical device, as shown in FIGS. 1 and 2, the opening 4 and the container for leading the optical fiber 11 connected to the optical device 10 housed inside to the outside. It is necessary to securely seal the housing 1 by filling the sealant 6 in the joint 6 between the cover member 20 and the cover member 20. However, there is also a problem that becomes apparent by filling the sealant. For example, the opening 4 has a large area to be filled with the sealant, and in order to “fill” the opening 4 by closing the sealant with the sealant, the surface tension of the sealant 4 is used. The sealant is filled to the periphery of the optical fiber 11 while supplying the sealant to the inner periphery, or the sealant is filled to the inner periphery of the opening 4 while supplying the sealant to the periphery of the optical fiber 11. Will be. In any case, a large amount of sealant is required.

  When the sealant is supplied from the inner periphery of the opening 4, the sealant enters the contact surface between the container 30 and the lid member 20 on the inner periphery due to capillary action, so that the opening 4 is sufficiently buried. There is a possibility of generating pinholes that can become a path for foreign matter and moisture. On the other hand, when the sealing agent is supplied around the optical fiber 11, the sealing agent travels through the optical fiber 11 and adheres to the connection site 12 in the optical device 10. When the sealant is cured, stress is applied to the optical fiber 11 and the connection member 12. The optical axis of the optical path formed between the optical fiber ports is precisely adjusted, and the optical axis is easily shifted by a slight external stress. The sealing agent also enters the gap between the connecting member 12 and the optical fiber 11 by capillary action, and when the sealing agent is cured there, a stress compressing in the radial direction is applied to the optical fiber 11, and this stress also The optical axis is shifted. If the optical axis is deviated, the loss when light emitted from one optical fiber port is coupled to the other optical fiber port increases.

  Therefore, the present invention can reliably seal the opening through which the optical fiber is led out with a small amount of sealing agent, and prevents deterioration of the optical characteristics of the internal optical device without applying unnecessary stress to the optical fiber. It is an object of the present invention to provide an optical device casing that can be used, and an optical device unit in which the optical device is accommodated in the casing.

The present invention for achieving the above object is a housing for storing an optical device connected to the optical fiber in a sealed state while leading the optical fiber extending in the front-rear direction to the outside,
A container portion in which the optical device is accommodated inward with a side surface standing upward around the bottom surface with the bottom as a bottom surface;
A box-shaped lid member having a top surface at the top and opening downward; and a tongue-like plate member installed inside the container portion;
With
The container part is formed with a container-side slit that opens at the upper end while extending from the lower side to the upper side on at least one of the front and rear sides.
The lid member is formed with a lid-side slit that extends from the upper side toward the lower side and opens at the lower end on at least one of the front and rear sides.
The lid member is attached to the container part and covers the opening and the side surface of the container part,
A rectangular opening for connecting the inside and outside of the housing by the container side slit and the lid side slit to lead out the optical fiber is formed,
The plate member is formed with a plate-side slit having a width in contact with the periphery of the optical fiber, and is in contact with the inner peripheral surface of the container-side slit.
This is a housing for an optical device characterized by this.

  More preferably, the plate-side slit extends in the left-right direction and is released at one of the left and right ends. An optical device housing in which a plurality of plate-side slits are formed in one plate member in parallel in the vertical direction is effective when a plurality of optical fibers are led out in the same direction.

  The openings are formed on both the front and rear surfaces, and the plate members are arranged on the front and rear sides, respectively, and the front and rear plate members are integrally continuous via a bottom plate portion in contact with the bottom surface of the container. An optical device casing in which a part of the metal plate is bent can also be used.

  It is good also as an optical device housing | casing by which the convex part which protrudes from the side surface of the said housing | casing is formed in the lower end of the said container side slit part. It can also be set as the optical device housing | casing which the hole for distribute | circulating internal and external air is opened.

  The present invention also extends to an optical device unit in which an optical device is housed in any of the above-described housings, and the optical device unit has an optical fiber outside through the plate-side slit and the opening. The seam between the container part and the lid member and the part connecting the inside and outside of the housing are sealed with a hardened sealing agent.

  According to the optical device casing of the present invention, the opening from which the optical fiber is led out can be reliably sealed with a small amount of sealant, and the internal optical device can be sealed without applying unnecessary stress to the optical fiber. Degradation of optical characteristics can be prevented. Further, in the optical device unit in which the optical device is housed in the housing, foreign matter and moisture do not enter the inside, and the optical characteristics are not deteriorated and the metal member due to the moisture is not corroded. Other effects will be clarified in the following description.

It is an external view of the housing | casing for conventional optical devices. It is a disassembled perspective view which shows the internal structure of the conventional housing | casing for optical devices. It is an external view of the housing | casing for optical devices which concerns on the Example of this invention. It is a disassembled perspective view which shows the internal structure of the housing | casing for optical devices which concerns on the said Example. It is a figure which shows the original shape of the baseplate member which comprises the housing | casing for optical devices which concerns on the said Example. It is a figure which shows the assembly method of the housing | casing for optical devices which concerns on the said Example. It is a figure for demonstrating the effect of the housing | casing for optical devices which concerns on the said Example. It is a figure which shows the housing | casing for optical devices which concerns on the other Example of this invention. It is a figure which shows the housing | casing for optical devices which concerns on the other Example of this invention.

  Embodiments of the present invention will be described below with reference to the accompanying drawings. Note that in the drawings used for the following description, the same or similar parts may be denoted by the same reference numerals and redundant description may be omitted. In some drawings, reference numerals may be assigned to parts that are not required in other drawings if unnecessary.

=== Example ===
3 and 4 show an optical device unit 100a in which an optical device is housed in an optical device housing (hereinafter also referred to as a housing 1a) according to an embodiment of the present invention. Here, the vertical and horizontal directions are defined in the same manner as the optical device unit 100 shown in FIGS. 3 is an external view of the optical device unit 100a, and FIG. 4 is an exploded perspective view showing the internal structure of the optical device unit 100a. As shown in FIG. 3, the housing 1 a has the same appearance as the conventional housing 1 shown in FIG. 1, and has an opening 4 for leading the optical fiber 11 to the front surface 2 and the rear surface 3 in a box shape. Is formed. However, in the case 1a according to the embodiment, in addition to the container portion 30 and the lid member 20, as shown in FIG. 4, the portions that rise upward in the form of tongue pieces at the front and rear ends (hereinafter also referred to as the tongue piece portion 41) are provided. The metal plate (henceforth the bottom plate member 40) provided is provided. In the illustrated bottom plate member 40, tongue pieces 41 are continuously formed on the left and right ends of the front and rear ends of the bottom 43 having a shape along the planar shape of the inner bottom 31 i of the container 30. As shown in FIG. 5, the bottom plate member 40 is initially a single metal plate 140 having protrusions 141 continuous at both front and rear ends of the bottom portion 43, and the tongue piece portion 41 is in the process of extending the protrusion 141 (in the drawing, It is formed by being raised upward from the dotted line 142). Of course, the front and rear tongue pieces 41 may be constituted by two separate members. However, if the front and rear tongue pieces 41 are formed integrally as in the embodiment 1a, the tongue piece 41 can be easily formed in the container 30. It can be installed inside and the number of parts is reduced. Thereby, an increase in manufacturing cost can be suppressed.

  The left and right width of the tongue piece 41 is slightly larger than the container-side slit 34, and the upper end coincides with the upper end of the container part. When the bottom portion 43 of the bottom plate member 40 is placed on the inner bottom surface 31 i of the container portion 30, the front surface of the front tongue piece portion 41 comes into contact with the inner peripheral surface of the front container side slit 34 and the rear surface of the rear tongue piece portion 41. Comes into contact with the inner peripheral surface of the rear container-side slit 34.

  The tongue piece portion 41 is formed with a slit extending in the left-right direction (hereinafter also referred to as a tongue piece slit 42), and this tongue piece slit 42 has a minimum vertical width necessary for leading out the optical fiber 11. Have. When the case 1a is assembled and the optical device 10 is accommodated therein, the optical fiber 11 is passed through each of the tongue piece slits 42 as shown in FIG. 6, and the bottom plate member 40 and the optical device 10 are placed in the container in this state. It is stored in the part 30. Then, after covering the lid member 20 on the container portion 30, the seam between the periphery of the outer bottom surface 31o of the container portion 30 and the lower end of the lid member 20, and the opening 4 is filled with a sealing agent such as an epoxy adhesive, If this is cured, the optical device 10 is sealed in the housing 1a, and the optical device unit 100a is completed.

  Here, the relationship between the filling state of the sealing agent in the housing 1a according to the embodiment and the sealing action of the internal space will be described. FIG. 7 is a view for explaining the sealing action. FIG. 7A shows a filling path 150 of the sealing agent 50 in the housing 1a according to the embodiment, and FIG. The filling path 150 of the sealing agent 50 in the conventional optical device casing 1 without the bottom plate member 40 as shown in FIG. FIG. 7C is a diagram illustrating a cured state of the sealant 50 in the housing 1a according to the embodiment, and FIG. 7D is a cured state of the sealant 50 in the conventional optical device housing 1. FIG.

  First, as shown in FIG. 7A, in the case 1 a according to the embodiment, when the opening 4 is filled with the sealant, the sealant can be applied to the surface 44 of the tongue piece 41. Therefore, the sealant is not the contact interface 110 between the lid member 20 and the container part 30 around the opening 4, but the contact interface 120 between the tongue piece part 41 and the container part 30, as shown by the thick arrow in the figure. It penetrates through capillary action. The penetration stops at the left and right edge 45 of the tongue piece 41. Further, since the periphery of the optical fiber 11 is in contact with the tongue piece 41, the tongue piece 41 is blocked even if the sealant flows in the direction of entering the housing 1 a along the optical fiber 11. Therefore, the supplied sealing agent effectively fills the opening 4. As a result, as shown in FIG. 7C, the opening 4 of the housing 1a is reliably closed in a state where the sealant 50 is deposited on the surface 44 of the tongue piece 41.

  On the other hand, as shown in FIG. 7B, in the case 1 of the related art, a sealant is supplied around the opening 4 or around the optical fiber 11. When supplying the sealant around the opening 4, the sealant penetrates into the contact interface 110 between the lid member 20 and the container part 30 by capillary action, so that more sealant is supplied than in Example 1a. There is a need. Further, when the opening 4 is sealed regardless of the supply path of the sealing material, the sealing material always adheres to the periphery of the optical fiber 11, and in the comparative example without the tongue piece 41, the sealing material is the optical fiber. 11 enters the housing 1. A part of the sealing agent that has entered the housing 1 may also enter the contact portion 13 between the optical fiber 11 and the connection member 12 in the optical device. Therefore, in the comparative example, as shown in FIG. 7D, if the penetration of the sealing material due to capillary action is not taken into consideration, the sealing agent that has filled the opening 4 penetrates even if the opening 4 is once blocked. As a result, the pinhole 51 may be generated in the opening 4. If the sealant 50 that has entered the housing 1 through the optical fiber 11 enters the contact portion 13 between the optical fiber 11 and the connecting member 12 in the optical device 10 and is cured, unnecessary stress is applied to the optical fiber 11. As a result, the optical axis between the optical fiber ports correctly adjusted when the optical device 10 is assembled is shifted.

<Characteristic evaluation>
3 and 4, the sealant made of an epoxy-based adhesive at the joint between the container portion 30 and the lid member 20 at the bottom 5 of the housing 1 a and the opening 4. Was filled and cured to seal the housing 1a. The sealed case 1a was first subjected to a waterproof test by a method based on JIS C 60068-2-17. And when the housing | casing 1a was decomposed | disassembled, it confirmed that the water | moisture content did not penetrate | invade inside the housing | casing 1a.

  Next, for the case 1a sealed in the same manner, it was confirmed whether or not optical properties were deteriorated due to the curing of the sealant. Here, the case (hereinafter also referred to as Example 1a) according to the embodiment shown in FIG. 3 and FIG. 4 and the case (hereinafter also referred to as comparative example) excluding the bottom plate member 40 from Example 1a are respectively illuminated. As the device 10, a 2 × 2 type mechanical optical switch was accommodated. And the optical characteristic of the optical device 10 was measured before and after sealing each opening part 4 of Example 1a and a comparative example with a sealing agent. Specifically, the optical device 10 is housed in Example 1a and the comparative example, and the optical device 10 is first driven before sealing the opening 4 with a sealant, and two predetermined lights facing each other in the front-rear direction. An optical path was formed between the fiber ports, and the optical coupling loss between the optical fiber ports was measured in this state. Next, the opening 4 was filled with a sealant, and the optical coupling loss was measured again after the sealant was cured. In addition, about the comparative example, the opening part 4 was sealed using the minimum amount of sealing agent required in order to pass a waterproof test.

  Table 1 below shows the measurement result of the optical coupling loss.

表１に示したように、実施例１ａでは開口部４を封止する前後での光結合損失が０．４ｄＢで光結合損失が変化していなかった。すなわち実施例１ａでは光軸のずれが発生しない。すなわち光ファイバ１１や光デバイス１０おける光ファイバ１１の接続部材１２に封止剤が付着せず、光ファイバ１１に不要な応力が掛かっていないことが確認できた。一方比較例では封止前の光結合損失は実施例１ａと同じ０．４ｄＢであったが、封止後には光結合損失が１．０ｄＢまで増加し光軸のずれが発生した。

As shown in Table 1, in Example 1a, the optical coupling loss before and after sealing the opening 4 was 0.4 dB, and the optical coupling loss did not change. That is, in Example 1a, the optical axis is not shifted. That is, it was confirmed that the sealing agent did not adhere to the optical fiber 11 or the connection member 12 of the optical fiber 11 in the optical device 10 and unnecessary stress was not applied to the optical fiber 11. On the other hand, in the comparative example, the optical coupling loss before sealing was 0.4 dB, the same as in Example 1a. However, after sealing, the optical coupling loss increased to 1.0 dB, and the optical axis shifted.

=== Other Embodiments ===
The optical device casing according to the present invention is not limited to the above-described embodiment 1a, but includes various modifications and application examples. FIG. 8 shows a housing 1b according to another embodiment of the present invention. FIG. 8A is a perspective view showing the container 30 constituting the housing 1b. FIG. 8B is a cross-sectional view of the housing 1b when viewed from the left-right direction. The housing 1b also includes a tongue piece 41 that abuts against the inner peripheral surface of the container-side slit 34. FIG. And in the housing | casing 1b which concerns on this Example, the convex part 35 which protrudes from the front surface 23 and the rear surface 24 of the cover member 20 is formed in the lower end of the container side slit 34, as shown to FIG. 8 (A). As a result, as shown in FIG. 8B, even if the sealing agent 50 filled in the opening 4 flows downward through the lid side slit 24, the convex portion 35 becomes a weir and the sealing agent 50. Can be prevented from flowing out from the lower end of the lid-side slit 24. That is, the opening 4 is more reliably closed and the amount of adhesive used can be reduced.

  In the optical device casing, the inside is filled with an adhesive filled in the inside or outside of the casing, such as a joint between the lid member and the container, or an opening, due to a pressure difference between the inside and outside of the casing for sealing the inside. There is a possibility that it will flow to the direction. This is a serious problem particularly when a thermosetting adhesive is used as the sealant. That is, the opening 4 is filled with a large amount of the sealing agent, and when the large amount of the sealing agent is thermally cured, the temperature of the housing itself also rises. For this reason, the pressure inside the casing, which is a closed space, increases, and there is a possibility that the sealing agent already filled in the seam, the other opening, or the like is ejected outward. Therefore, as in the case 1c shown in FIG. 9, a small hole (hereinafter also referred to as an air circulation hole 60) is provided on the top surface 21 of the lid member 20 to connect the inside and outside, and a pressure difference is generated inside and outside the case 1c. It may not be possible. And when sealing the housing | casing 1c, what is necessary is just to seal this air circulation hole 60 last. The air circulation hole 60 can be formed anywhere on the surface of the housing 1c. However, in the portion where the lid member 20 and the container part 30 are in contact such as a side surface, the air circulation hole 60 is in the same position on both the lid member 20 and the container part 30 The flow hole 60 is formed.

  In Example 1a, the tongue piece slit 42 is orthogonal to the extending direction of the slits (34, 24) of the container 30 and the lid member 20, but may be parallel. In this case, the tongue piece and the slit on the housing side extend in the same direction, and the sealant easily flows along the extending direction. Further, the optical fiber cannot be supported until the sealing material is cured. Therefore, it becomes easy for the optical fiber 11 to move in the extension direction of the slit with the flow of the sealant. In particular, in the case where a plurality of optical fibers 11 are led out from one side as in Example 1a, a jig or the like is used until the sealing material is cured to some extent in order to maintain a constant spacing between the plurality of optical fibers. It must be used to support the optical fiber.

  As a matter of course, the optical device housed in the housing is not limited to a 2 × 2 type mechanical optical switch, but may be any optical device with an optical fiber connected thereto. Of course, the optical fiber is not limited to both the front and rear surfaces, and may be led out from either the front or back surface.

1, 1a to 1c optical device casing, 4 openings, 10 optical device,
11 optical fiber, 20 lid member, 24 lid side slit, 30 container part,
34 container side slit, 35 convex part, 40 bottom plate member, 41 tongue piece part,
42 Tongue piece slit, 50 Sealant, 60 Air flow hole

Claims (7)

A housing for storing an optical device connected to the optical fiber in a sealed state while leading out the optical fiber extending in the front-rear direction,
A container portion in which the optical device is accommodated inward with a side surface standing upward around the bottom surface with the bottom as a bottom surface;
A box-shaped lid member having a top surface at the top and opening downward; and a tongue-like plate member installed inside the container portion;
With
The container part is formed with a container-side slit that opens at the upper end while extending from the lower side to the upper side on at least one of the front and rear sides.
The lid member is formed with a lid-side slit that extends from the upper side toward the lower side and opens at the lower end on at least one of the front and rear sides.
The lid member is attached to the container part and covers the opening and the side surface of the container part,
A rectangular opening for connecting the inside and outside of the housing by the container side slit and the lid side slit to lead out the optical fiber is formed,
The plate member is formed with a plate-side slit having a width in contact with the periphery of the optical fiber, and is in contact with the inner peripheral surface of the container-side slit.
An optical device casing characterized by the above.   2. The optical device casing according to claim 1, wherein the plate-side slit extends in the left-right direction and is released at one of the left and right ends.   3. The optical device casing according to claim 2, wherein a plurality of the plate side slits are formed in one plate member so as to be arranged in parallel in the vertical direction.   In any one of Claims 1-3, while the said opening is formed in both front and back surfaces and the said plate member is each arrange | positioned at the front and back, the said front and back plate member is the bottom plate which touches the bottom face of a container. A case for an optical device, wherein a part of a single metal plate that is integrally continuous is bent.   5. The optical device casing according to claim 1, wherein a convex portion protruding from a side surface of the casing is formed at a lower end of the container-side slit portion.   6. The optical device casing according to claim 1, wherein a hole for allowing the inside and outside air to circulate is opened. An optical device unit in which an optical device is accommodated in the housing according to claim 1,
An optical fiber is led out through the plate side slit and the opening,
A seam between the container part and the lid member and a portion connecting the inside and outside of the housing are sealed with a hardened sealant.
An optical device unit characterized by that.

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